In the conventional reciprocating IC engines, (in-line, V, opposed) the main moving components include: the pistons, the connecting rods, and the crankshaft. In yoke-type engines, according to prior art (e.g. U.S. Pat. Nos. 3,517,652, 4,013,048, 4,485,768), opposed pistons are rigidly connected to each other and various types of slider mechanisms are used to transmit the reciprocating motion of the pistons to a rotating motion of a crankshaft. Other opposed piston engines use various types of camshafts, gear mechanisms, rollers and guides with various piston return means in place of the conventional connecting-rods and crankshaft. (e.g. U.S. Pat. No. 4,510,894, 4,408,578, 4,641,611, 4,682,569). Still other types of engines have pistons parallel to a driveshaft (e.g. U.S. Pat. No. 4,453,504). All these prior art opposed piston engines have mostly become more complicated, with more moving parts, than conventional in-line, V- and opposed engines, and therefore, have mostly not received acceptance among engines manufacturers.
Other prior art patents that have come to my attention include U.S. Pat. Nos. 3,383,603 and 3,828,655.